Combined use of LC–ESI-MS and antifungal tests for rapid identification of bioactive lipopeptides produced by Bacillus amyloliquefaciens CCMI 1051

The strain Bacillus amyloliquefaciens CCMI 1051 used in this study has been isolated in our laboratory from healthy Quercus suber in the south of Portugal and shows high levels of antagonistic properties against filamentous fungi that attack forest products industry due to the production of bioactive peptides. A combined use of LC–ESI-MS and antifungal tests allowed a rapid identification of lipopeptides as active compounds produced. Applying autobiographic methods it was possible to obtain active compounds. LC–ESI-MS, a powerful tool for rapid identification, indicates the presence of lipopeptides and MS2 electrospray ionization showed the partial sequence Tyr–Asn–Pro–Glu in the peptidic portion of some compounds produced. The association of mass spectrometry and chromatography, used in parallel with antifungal tests proved to be an efficient approach for the characterization of active lipopeptides without the need of previous total isolation. This methodology can be employed for screening and optimization the production of antifungal iturinic lipopeptides, showing a great potential for future application

Effect of fat content, casing type and smoking procedures on PAHs contents of Portuguese traditional dry fermented sausages

Portuguese dry fermented sausages are traditionally processed through direct drying/smoking, making them susceptible to polycyclic aromatic hydrocarbons (PAHs) contamination. The purpose of this study was to assess the effect of added fat (20% and 40%), casing type (hog and collagen) and smoking procedures (direct and indirect exposure) on the 16 EPA priority PAHs in dry fermented sausages manufactured according traditional processing. The total PAHs content (sum of 16 PAHs) found in whole product (casing included) varied between 150 and 870 lg kg 1, with more than 99% of this content corresponding to harmless low molecular weight compounds. Concerning benzo(a)pyrene (BaP) and PAH4, the respective maximum contents (0.32 and 10.35 lg kg 1, respectively) did not exceed the imposed limits regulated by the European Union. According to our results, casing type was the most influential factor. For hog samples, fat content and smoking regime alone did not influenced the total PAHs amount. However, significantly higher (p < 0.05) contamination levels were detected in hog casing samples combining high fat content and direct smoking procedures. In opposition, irrespective of the fat content and smoking regime, safer products, with significantly lower (p < 0.001) contamination levels, were obtained when collagen casing was used

Computational intelligence techniques in engineering

This article shows how CI techniques overpass the strict limits of Artificial Intelligence (AI) field and can help solving real problems from distinct engineering areas: Mechanical, Computer Science and Electrical Engineering. An introduction to each of the CI main areas is made and three systems are briefly described. The results are, in each case, very promisingN/

The Effect of starter Cultures on the Portuguese Traditional Sausage "Paio do Alentejo" in Terms of its Sensory and Textural Characteristics and Polycyclic Aromatic Hydrocarbons Profile

“Paio do Alentejo” is a Portuguese dry-cured sausage, made with meat from the Alentejano pig breed. The main aim of this study is to evaluate the benefits of the use of starter cultures on the quality of the sausage, mainly with regard to its sensory properties, rheological characteristics and PAH profile. Three batches of the product were examined: S1-inoculated with a commercial starter comprising Lactobacillus spp., Micrococcaceae and yeasts; S2-inoculated with a starter comprising Lactobacillus sakei and Staphylococcus xylosus; C-the control batch, was not inoculated. A sensory panel of 12 experts analysed samples in accordance with a descriptive analysis using a structured scale. A Texture Profile Analysis and 16 EPA priority PAHs for dry fermented sausages were performed. Both inoculated batches were well received by the judges, no significant differences being noted between them. The use of S2 led to a slight improvement in terms of cohesiveness. However, the use of starter cultures was not found to influence PAH content

Modelling of Bacillus Amyloliquefaciens CCMI 1051 Cultures Using Artificial Intelligence Based Tools

It is well known that Bacillus species produce a wide variety of metabolites with interesting biological activities, namely antibiotic compounds as iturinic lipopeptides, being the aspartic acid a favourable nitrogen source for iturinic compounds production by B. subtilis and by B. amyloliquefaciens. The incubation time is another factor to be considered on antibiotic production. On the other hand, Artificial Neural Networks (ANN) are widely accepted as a tool that offers an alternative way to tackle complex problems. They can learn from examples, are fault tolerant in the sense that they are able to handle noisy and incomplete data, are able to deal with non-linear problems, and once trained can perform prediction and generalization at high speed. The prediction of Bacillus sporulation (BS) and antifungal activity of compounds (AFA), from incubation time of cultures (IT) and from aspartic acid concentration (AA) is a complex and highly nonlinear problem for which there are no known methods to predict them directly and accurately. The aim of this study is to optimize the production of antifungal compounds in B. amyloliquefaciens CCMI 1051 cultures using ANN. The database to be used contains antifungal data of cultures with different IT (1-9 days) using AA (0.4-5.6 g/L) as nitrogen source. In order to obtain the best prediction of the AFA and BS, different network structures and architectures have to be elaborated. The optimum number of hidden layers and the optimum number of nodes in each of these will be found by trial and error. The model being depicted above was in mean time accomplished, and the results obtained with it appointed that the maximum AFA is achieved with 2.6 g/L of aspartic acid on day 9. However, with AA of 4.8 g/L a similar maximum value of activity is obtained for incubation time over 6 days. The model shows a dual behaviour for AFA, depending of the IT. When the IT is higher than 5 days the AFA versus AA shows a pronounced sigmoid profile, converging to a common maximum value of AFA. On the other hand, for IT lower than 5 days mentioned profile is ill-defined and the common converging point isn’t observed. The conclusion is that the use of ANNs show to be a potent computational tool that must be present in any intelligent predictive task applied to Bacillus cultures, evidencing nitrogen source as key factor to be considered in these kind of problems, where the time of incubation plays a role in secondary production of active compounds

Rede Nacional de Cuidados Continuados Integrados – o seu impacto no funcionamento de um Serviço de Urologia

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Surface response methodology towards optimal carotenoids production by Gordonia Alkanivorans Strain 1B [Poster]

ABSTRACT: The process of obtaining carotenoids, mainly towards sectors that may influence the human health, such as pharmaceutical and cosmetic, is strictly regulated because of the potential toxicity of the synthetically derived pigments. Thus, microbial pigments are in increasing demand since they are a promising natural and safe alternative source for various industrial applications. Gordonia alkanivorans strain 1B is a fructophilic desulfurizing bacterium, which was also shown to be a good producer of carotenoids. However, its production abilities presented a great variation, depending on the conditions it was submitted to. In previous works, both the carbon source and sulfur source, demonstrated a great influence in the total carotenoid concentration, especially when combined with the presence of a light source. So, in this study, a surface response methodology based on the Doehlert distribution for two factors (% of glucose in a mix glucose + fructose (10 g/L total sugars), and sulfate concentration) was used aiming to get the optimal carotenoids production by G. alkanivorans strain 1B.N/

Imidazole processing of wheat straw and eucalyptus residues: comparison of pre-treatment conditions and their influence on enzymatic hydrolysis

ABSTRACT: Biomass pre-treatment is a key step in achieving the economic competitiveness of biomass conversion. In the present work, an imidazole pre-treatment process was performed and evaluated using wheat straw and eucalyptus residues as model feedstocks for agriculture and forest-origin biomasses, respectively. Results showed that imidazole is an efficient pre-treatment agent; however, better results were obtained for wheat straw due to the recalcitrant behavior of eucalyptus residues. The temperature had a stronger effect than time on wheat straw pre-treatment but at 160 degrees C and 4 h, similar results were obtained for cellulose and hemicellulose content from both biomasses (ca. 54% and 24%, respectively). Lignin content in the pre-treated solid was higher for eucalyptus residues (16% vs. 4%), as expected. Enzymatic hydrolysis, applied to both biomasses after different pre-treatments, revealed that results improved with increasing temperature/time for wheat straw. However, these conditions had no influence on the results for eucalyptus residues, with very low glucan to glucose enzymatic hydrolysis yield (93% for wheat straw vs. 40% for eucalyptus residues). Imidazole can therefore be considered as a suitable solvent for herbaceous biomass pre-treatment.info:eu-repo/semantics/publishedVersio

Sugarcane bagasse delignification with potassium hydroxide for enhanced enzymatic hydrolysis

The optimization of an alkaline pretreatment process for the delignification of sugarcane bagasse (SCB) to enhance the subsequent enzymatic hydrolysis was performed according to the Doehlert uniform shell design. In this experimental design, the effect of two factors—potassium hydroxide (KOH) concentration and autoclaving time at 121 C (1 atm)—on cellulose, hemicellulose, or the total polysaccharide and lignin content in SCB was evaluated. This response surface methodology revealed that KOH concentration is the factor that most influences the chemical characteristics of treated SCB (SCBt), with optimal conditions for the highest delignification being KOH in the range 5–10% (w/v) and an autoclaving time of 35 min, which provides an average of 97% total polysaccharides without inhibitor accumulation (furfural, 5-hydroxymethyl furfural) and #5% lignin. SCBt samples from two pretreatment conditions (KOH 3.25% – 13 min; KOH 10% – 35 min) were selected, based on the greatest delignification (70–74%) and polysaccharide availability (95–97%) after pretreatment, and further hydrolysed for fermentable sugar production. High sugar yields were obtained from both the pretreated samples (866 to 880 mg sugar per g biomass, respectively) in contrast with the 129 mg sugar per g raw biomass obtained from untreated SCB. These results demonstrate the effectiveness of KOH alkali pretreatments, which improves the overall digestibility of raw SCB polysaccharides from about 18% up to 91%. However, harsh alkali treatment (KOH 10%) is the most effective if the highest glucose/xylose ratio in the final sugar-rich hydrolysate is the aim. Hence, the use of sugar-rich hydrolysates obtained from SCBt as the carbon source for industrial purposes may provide a sustainable and economic solution for the production of bio-based added-value products, such as second generation (2G) bioethanol

Crustal stretching process denounced by mafic magmatism in the Finisterra Terrane; the yield of a back-arc basin?

The occurrence of a new tectono-stratigraphic terrane (Finisterra Terrane), located in the westernmost domains of the Porto-Tomar-Ferreira do Alentejo Shear Zone, has been highlighted in the last few years. Nevertheless, there are several gaps in the geological knowledge of this Terrane, including the interpretation of existing data in the framework of the new tectono-stratigraphic terrane proposal, with an independent evolution from the Iberian Terrane. This work is an approach to the mafic magmatism significance that is described in the tectono-stratigraphic units from Abrantes-Tomar and Porto-Espinho-Albergaria-a-Velha sectors of the Finisterra Terrane. The geochemical data of the amphibolite rocks show affinities with mafic and ultramafic protholits with geochemical features between within-plate basalts and MORB. These amphibolites express specific geochemical features (e.g. N-MORB normalized Ba and Th enrichments, as well as Nb and Ta anomalies), suggesting their emplacement in a back-arc basin tectonic setting